Consider the scope of this ticket to be just the replicasets and sharding tests on Linux 64. We need to figure out if the slowdown seen in our test suites is expected or unexpected behavior.

replicasets - usually 1 hour and 5 minutes
replicasets_auth - usually 2 hours and 15 minutes

sharding - usually 50 minutes
sharding_auth - usually 2 hours and 20 minutes